I have ZA Firewall since a year now while upgrade the ZA when it;s avaliable new version of ZA Firewall..
if you want very strong stealth mode, go to SECURITY tab and move the both sides all way to TOP as HIGH settings. if you want to DCC chat with your Bots and you need to turn off the "block" on Local/Internet setting bottom of the security settings. after that your chat is DONE with DCC Chat with bots, you can turn back on BLOCK both Local and Internet..
Also on MIRC: Turn off the IDENT in your mirc settings cuz of the ZA would detected ident port 13.
The test port probe avaliable at
www.grc.org or com I forgot the GRC site addy..
I've hits lot of ports detected from outside of internets,, 111,12345 and lot of suspectable ports.. it;s totally BLOCKED and very heavy stealth mode,, the hacker cannot find you when your ZA is Stealth Mode ON (Both must be HIGH on security settings)